In the field of video compression, communication, decompression, and display, there has been for many years problems associated with supporting both interlaced content and interlaced displays, along with progressive content and progressive displays. Many advanced video systems support either one or the other format. As a result such devices as deinterlacers have become important components in many video systems. Deinterlacers convert interlaced video format into progressive video format.
Deinterlacing takes interlaced video fields and coverts them into progressive frames, at double the display rate. Certain problems may arise concerning the motion of objects from image to image. Objects that are in motion are encoded differently in interlaced fields from progressive frames. Video images, encoded in deinterlaced format, containing little motion from one image to another may be deinterlaced into progressive format with virtually no problems or visual artifacts. However, problems arise with video images containing a lot of motion and change from one image to another, when converted from interlaced to progressive format. As a result, some video systems were designed with motion adaptive deinterlacers.
Today, motion adaptive deinterlace video systems rely on multiple fields of data to extract the highest picture quality from a video signal. When motion is detected between fields, it may be very difficult to use temporal information for deinterlacing. Instead, a deinterlacing circuit must utilize a spatial filter (usually a vertical filter of the field of interest). However, often the source material has diagonal lines, or curved edges, and using a spatial filter may not yield satisfactory results. For example, diagonal or curved edges will be represented with stair-step or jaggies that are visible in the image.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.